package com.lw.question09;

import java.util.Scanner;

/**
 * @author LW
 * @2020/9/16 22:30
 */
public class 奇数位3 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int s = scanner.nextInt();
        String str = String.valueOf(s);
//        System.out.println(str.charAt(0));
        char[] c = str.toCharArray();
        String str1 ="";
        //从低位开始取出 s 中的 奇数位 上的数
        for (int i = 0; i < c.length; i++) {
            if ((c.length-i)%2!=0){
                str1 +=c[i];
                System.out.println(str1);
            }
        }
        int sum = Integer.parseInt(str1);
        System.out.println(sum);
    }
}
